Leather belting



May 25, 1943.

H. J. sHlvELL 2,320,158

LEATHER BELTING Filed May l0, 1940 HOMER ,J sH/VQL Patente-cl May 25, 1943 UNITED STATES PATENT OFFICE LEATHER BEL'rING Homer J. Shivell, Kingsport, Tenn. v

Application May 10, 1940, Serial No. 334,299 s claims. (omi- 232) This application relates to leather belting, and especially to a new and improved manner of producing a leather belting.

Leather belting has been manufactured in one or more plys, and one of the major diiculties which has been encountered in its use has been the stretch which takes place during use, and which necessitates tightening of the belt to prevent slippage. Another problem has been the tendency of surface cracks to develop, which ultimately may extend entirely through and break the belt.

Furthermore, leather belting may be adversely affected by moisture, and more particularly by oils, such as common lubricating or machine oils.

It is one object of my inventiony to-construct a belt which will have most of the :stretch removed before it is placed in service.

It is another object of myy invention to use unstretched or only partially stretched grain leather against the pulley. l l

It is another object of my invention to produce a leather having a greater tensile strength than ordinary belting, for the same cross-sectional area.

It is another object of my invention to produce a belt that will resist the deteriorating action of oils and greases.

It is another object to make possible a belt having a greater number of plies than has hitherto been possible, whereby to transmit a greater horsepower.

It is still another object of my invention to produce a belt which can adjustitself more fully to the arc of a pulley, and thereby be a more effective transmission medium.

In the accompanying drawing I have shownv Cal tions, each as may be best suited to the requirements of any particular use.

Other objects will be apparent from the following specication and the annexed drawing, in which:

Fig. 1 is a view of a reconstructed single ply belt made in accordance with my invention and operating over a motor pulley and a shaft drive pulley:

Fig. 2 is a cross section through the line 2--2 of Fig. 1 and showing the method of lamination; Fig. 3 is a cross section of a belt in which a flesh split has been substituted for the grain, and Figure 4 is a cross-section of a multi-ply belt made in accordance with my invention. Beltleather as it comes from the hide of the animal consists of two parts. About two-thirds of the thickness of such a piece of leather is the part next to the esh known as the flesh split and is made up of strong long fibres and provides most of .the strength of the leather. The top third on the outside or hair side is made up about half of grain, which is the `outside of the hide, and about half of a' binder material which binds the grain to the flesh split. The grain part of the hide is capable of about 1012% stretch, at which point it reaches its yield point, andfurther stretching will damage its structure and reduce the tensile strength of the leather.

The flesh split, on the other hand, is capable of a stretch of 15-20% without damage, and normally when a belt consisting of unsplit leather is used the esh split does stretch further, resulting in loosening of the belt and cracking of the grain, which ultimately results in failure of the belt.

In preparing the leather for a belt in accordance with my invention, the grain is split away from the flesh split by a splitting machine, and the fiesh split is then stretched the allowable amount, e. g., 15-20%, which may be l5-90% of its available stretch without damage. After this stretching process is complete, the leather is again run through a splitting machine where the high spots are removed, bringing the leather down to a uniform thickness.

In the case of a single ply belt, i. e., one having but a single layer of leather, I nd it advantageous to laminate back the unstretched layer of grain which was originally removed. It will be necessary, of course, to add additional grain, since the stretched flesh split is 15-20% greater in length than the unstretched grain taken from the same piece of hide, but this additional grain is readily procurable from the excess grain available from manufacture of multi-ply belts.

The resulting belt is shown in Figs. 1 and 2,

where the grain I has been cemented back onto` the flesh split 2, with a layer of cement 3 which, for example, may advantageously be a cellulose acetate adhesive mixture. In Fig. 1 the grain the Wearing surface against the motor pulley l0 and the shaft pulley I2. Thus the wear and abrasion comes upon a part of the leather which is not under substantial tension, and minor cuts, cracks or scratches do not tend to pull out into serious tears. Instead of cementing a layer of grain to form the surface a layer 0f unstretched or partially stretched flesh split may be used.

In the making of a multi-ply belt, as shown in Fig. 4, several strips of leather 2a, 4a and 6a are cut out and split as described in connection with the reconstructed single ply belt described above and shown in Figs. 1 and 2. Instead of merely reconstructing the leather, however, these several strips of prestretched flesh split leather are cemented together to form a much thicker belt, as is shown in Fig. 4. The absence of grain and the prestretching results in a belt which withstands the ilexing when passing over the pulleys much better than a beltmadej according to prior methods. After the belt is completed it may be run through a sanding machine, i. e., one'which sands off the high spots, and it reduces the entire belt to a uniform thickness. Following this sanding the belt may be placed in a solution of shellac and non-oxidizing animal greases and allowed to soak for a considerable period of time, e. g., until the mixture has sunk into the innermost part of the belting. It will be found that the greases sink into the fibres of the leather, while the shellac will stick on the surface, but the final eect will be a leather belt which willbe resistant to the veiTects of moisture or damaging oils, such as machine oil.

In the form of my invention shown in Fig. 3, instead of producing a restored single ply belt as shown in Figs. 1 or 2, or a multi-ply belt as shown in Fig. 4, Ihave shown a belt in which the-grain, instead of being replaced as in the reconstructed single ply, has substituted in its is advantageously on the inside, so that it formsplace another layer of flesh split. This method of belt making, while retaining the stretchless advantage of the reconstructed single ply belt, results in a belt which has a tensile strength of considerably higher value than Ythat of the reconstructed single ply, and yet is of ,but slightly greater thickness. As heretofore stated, this ply which is in contact with the pulley may be stretched to a lesser degree than the other ply, whereby to obtain a better wearing surface.

When a multi-ply belt'is constructed in accordance with my invention it may be advantageous to cement to the surface which engages the pulleys a layer of unstretched or partially stretched grain, or unstretched or partially stretched flesh split, as in the reconstructed single ply belt, in order to provide a bearing surface which is essentially unstrained, and Will not be subject to the cracking of a surface under full tension. It may also be advantageous to stretch each layer of leather to a different degree, so that the belt may more easily pass over the pulleys. y

What I claim is:

1. 'Ihemethod of preparing a leather adapted for use in belting and the like which comprises removing the grain from the flesh split, stretching the ilesh split, and reconstructing the leather by cementing the unstretched grain back onto the stretched ilesh split.

2. The method of preparing a leather for use in belting and the like which comprises splitting the grain from the esh split of a tanned hide, stretching said ilesh split, levelling said ilesh split by removing any high spots, and laminating and securing together said flesh'split to the unstretched grain.

3. A leather product' of the type which is subjected inuse to severe stresses longitudinal ofthe leather, which comprises a layer of prestretched flesh split and a layer of unstretched grain cemented thereto. i

HOMER J. -SHIVELL 

